futex_64.h

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#ifndef _SPARC64_FUTEX_H
#define _SPARC64_FUTEX_H

#include <linux/futex.h>
#include <linux/uaccess.h>
#include <asm/errno.h>

#define __futex_cas_op(insn, ret, oldval, uaddr, oparg) \
    __asm__ __volatile__(               \
    "\n1:   lduwa   [%3] %%asi, %2\n"       \
    "   " insn "\n"             \
    "2: casa    [%3] %%asi, %2, %1\n"       \
    "   cmp %2, %1\n"           \
    "   bne,pn  %%icc, 1b\n"            \
    "    mov    0, %0\n"            \
    "3:\n"                      \
    "   .section .fixup,#alloc,#execinstr\n"    \
    "   .align  4\n"                \
    "4: sethi   %%hi(3b), %0\n"         \
    "   jmpl    %0 + %%lo(3b), %%g0\n"      \
    "    mov    %5, %0\n"           \
    "   .previous\n"                \
    "   .section __ex_table,\"a\"\n"        \
    "   .align  4\n"                \
    "   .word   1b, 4b\n"           \
    "   .word   2b, 4b\n"           \
    "   .previous\n"                \
    : "=&r" (ret), "=&r" (oldval), "=&r" (tem)  \
    : "r" (uaddr), "r" (oparg), "i" (-EFAULT)   \
    : "memory")

static inline int futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
{
    int op = (encoded_op >> 28) & 7;
    int cmp = (encoded_op >> 24) & 15;
    int oparg = (encoded_op << 8) >> 20;
    int cmparg = (encoded_op << 20) >> 20;
    int oldval = 0, ret, tem;

    if (unlikely(!access_ok(VERIFY_WRITE, uaddr, sizeof(u32))))
        return -EFAULT;
    if (unlikely((((unsigned long) uaddr) & 0x3UL)))
        return -EINVAL;

    if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
        oparg = 1 << oparg;

    pagefault_disable();

    switch (op) {
    case FUTEX_OP_SET:
        __futex_cas_op("mov\t%4, %1", ret, oldval, uaddr, oparg);
        break;
    case FUTEX_OP_ADD:
        __futex_cas_op("add\t%2, %4, %1", ret, oldval, uaddr, oparg);
        break;
    case FUTEX_OP_OR:
        __futex_cas_op("or\t%2, %4, %1", ret, oldval, uaddr, oparg);
        break;
    case FUTEX_OP_ANDN:
        __futex_cas_op("andn\t%2, %4, %1", ret, oldval, uaddr, oparg);
        break;
    case FUTEX_OP_XOR:
        __futex_cas_op("xor\t%2, %4, %1", ret, oldval, uaddr, oparg);
        break;
    default:
        ret = -ENOSYS;
    }

    pagefault_enable();

    if (!ret) {
        switch (cmp) {
        case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
        case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
        case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
        case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
        case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
        case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
        default: ret = -ENOSYS;
        }
    }
    return ret;
}

static inline int
futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
                  u32 oldval, u32 newval)
{
    int ret = 0;

    __asm__ __volatile__(
    "\n1:   casa    [%4] %%asi, %3, %1\n"
    "2:\n"
    "   .section .fixup,#alloc,#execinstr\n"
    "   .align  4\n"
    "3: sethi   %%hi(2b), %0\n"
    "   jmpl    %0 + %%lo(2b), %%g0\n"
    "   mov %5, %0\n"
    "   .previous\n"
    "   .section __ex_table,\"a\"\n"
    "   .align  4\n"
    "   .word   1b, 3b\n"
    "   .previous\n"
    : "+r" (ret), "=r" (newval)
    : "1" (newval), "r" (oldval), "r" (uaddr), "i" (-EFAULT)
    : "memory");

    *uval = newval;
    return ret;
}

#endif /* !(_SPARC64_FUTEX_H) */